I once encountered a fellow at the ramp who made fun of my obsessing over strapping down the bow eye. He and his buddies drove off laughing. I encountered him at the first stop light and saw that his entire boat had hopped off the trailer and landed smack in the middle of the road. He just stood there slack-jawed as I cruised past.
The winch has limited ability to keep the bow on the trailer when a momentary bump or sudden trailer drop occurs. We can depend on gravity to do lots of things, but inertia can and will rule the day in the end. I never like to gamble. Have you watched the bow of your boat closely while you travel at highway speeds? Chances are that if you had, you would understand why I strapped mine down. I think it saved my bacon during one particular panic stop on the interstate. As I said, people may make fun of you at the ramp, but you will arrive intact wherever you go if the bow is strapped (along with the rear eyes of course).
Keep an eye on the axle hangers, a u-shaped channel that each axle is bolted to. They have "ears" at each end that can develop cracks across them where the u-bolts attach to the trailer tube.
I found that my Marathons didn't wear evenly and died premature deaths. I moved over to Towmasters and finally settled on Kumho commercial truck tires. They lasted several years until I sold her. Not much difference in price either. I bet the 5th wheelers also have plenty of advice for good rubber. I do know that when you dunk the trailer in salt you MUST rinse it as soon as practically possible to avoid corrosion. It is amazing how much hardware on trailers turns out to be NOT stainless. And you have to tear apart your bearings for inspection and new seals every year. Getting dunked after running on the road means that they get cooled quickly and water goes in there, despite your best efforts to prevent it. Be sure to use a REAL marine grease for the trailer bearings and not some generic do-it-all stuff. I used several brands but was partial to the better names.
Say, be sure to pull the prop and lube the shaft yearly too. They get frozen if neglected. Shoot me a message for more tips on Yamaha outboards. I had a F150 - Sweet motors! They are so quiet that I've seen people forget to turn 'em off when they pull the boats out of the water. It only takes about 15-30 seconds to melt the seals on the water pump when out of the water. Always keep her submerged when running. And don't crank her when on muffs until the lower unit fills, or run it in a barrel.
Anyway, Bless you my son! Go and live life to the fullest with your wonderful craft! Be sure to post more pics of the WC and boat combo in scenic situations. I never tire of seeing TC's getting out in the world!